The present invention is directed to developer compositions. More specifically, the present invention is directed to dry and liquid electrographic toners containing specific colorants. One embodiment of the present invention is directed to a toner composition for the development of electrostatic latent images comprising particles comprising a mixture of a resin and a colorant selected from the group consisting of: (a) those of Formula I ##STR3## wherein R.sub.1 is an electron withdrawing group, R.sub.2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, R.sub.3 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, and Ar is selected from the group consisting of aryl, substituted aryl, arylalkyl, and substituted arylalkyl; (b) those of Formula II ##STR4## wherein R.sub.1 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, R.sub.2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, and Ar is selected from the group consisting of aryl, substituted aryl, arylalkyl, and substituted arylalkyl; (c) dimeric compounds containing two moieties of Formula I; (d) dimeric compounds containing two moieties of Formula II; (e) dimeric compounds containing one moiety of Formula I and one moiety of Formula II; (f) trimeric compounds containing three moieties of Formula I; (g) trimeric compounds containing three moieties of Formula II; (h) trimeric compounds containing two moieties of Formula I and one moiety of Formula II; (i) trimeric compounds containing one moiety of formula I and two moieties of Formula II; (j) polymeric compounds containing at least four moieties selected from the group consisting of Formula I, Formula II, and mixtures thereof; and (k) mixtures thereof.
Another embodiment of the present invention is directed to a liquid developer composition for the development of electrostatic latent images which comprises a nonaqueous liquid vehicle and a colorant selected from the group consisting of: (a) those of Formula I ##STR5## wherein R.sub.1 is an electron withdrawing group, R.sub.2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, R.sub.3 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, and Ar is selected from the group consisting of aryl, substituted aryl, arylalkyl, and substituted arylalkyl; (b) those of Formula II wherein R.sub.1 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, R.sub.2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, and Ar is selected from the group consisting of aryl, substituted aryl, arylalkyl, and substituted arylalkyl; (c) dimeric compounds containing two moieties of ##STR6## Formula I; (d) dimeric compounds containing two moieties of Formula II; (e) dimeric compounds containing one moiety of Formula I and one moiety of Formula II; (f) trimeric compounds containing three moieties of Formula I; (g) trimeric compounds containing three moieties of Formula II; (h) trimeric compounds containing two moieties of Formula I and one moiety of Formula II; (i) trimeric compounds containing one moiety of formula I and two moieties of Formula II; (j) polymeric compounds containing at least four moieties selected from the group consisting of Formula I, Formula II, and mixtures thereof; and (k) mixtures thereof, wherein the liquid developer has a resistivity of from about 10.sup.8 to about 10.sup.11 ohm-cm and a viscosity of from about 25 to about 500 centipoise.
Yet another embodiment of the present invention is directed to a liquid developer composition for the development of electrostatic latent images which comprises a nonaqueous liquid vehicle, a charge control agent, and toner particles comprising a mixture of a resin and a colorant selected from the group consisting of: (a) those of Formula I ##STR7## wherein R.sub.1 is an electron withdrawing group, R.sub.2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, R.sub.3 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, and Ar is selected from the group consisting of aryl, substituted aryl, arylalkyl, and substituted arylalkyl; (b) those of Formula II ##STR8## wherein R.sub.1 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, R.sub.2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, and substituted arylalkyl, and Ar is selected from the group consisting of aryl, substituted aryl, arylalkyl, and substituted arylalkyl; (c) dimeric compounds containing two moieties of Formula I; (d) dimeric compounds containing two moieties of Formula II; (e) dimeric compounds containing one moiety of Formula I and one moiety of Formula II; (f) trimeric compounds containing three moieties of Formula I; (g) trimeric compounds containing three moieties of Formula II; (h) trimeric compounds containing two moieties of Formula I and one moiety of Formula II; (i) trimeric compounds containing one moiety of formula I and two moieties of Formula II; (j) polymeric compounds containing at least four moieties selected from the group consisting of Formula I, Formula II, and mixtures thereof; and (k) mixtures thereof.
The formation and development of images on the surface of photoconductive materials by electrostatic means is well known. The basic electrophotographic imaging process, as taught by C. F. Carlson in U.S. Pat. No. 2,297,691, entails placing a uniform electrostatic charge on a photoconductive insulating layer known as a photoconductor or photoreceptor, exposing the photoreceptor to a light and shadow image to dissipate the charge on the areas of the photoreceptor exposed to the light, and developing the resulting electrostatic latent image by depositing on the image a finely divided electroscopic material known as toner. Toner typically comprises a resin and a colorant. The toner will normally be attracted to those areas of the photoreceptor which retain a charge, thereby forming a toner image corresponding to the electrostatic latent image. This developed image may then be transferred to a substrate such as paper. The transferred image may subsequently be permanently affixed to the substrate by heat, pressure, a combination of heat and pressure, or other suitable fixing means such as solvent or overcoating treatment.
Another known process for forming electrostatic images is ionography. In ionographic imaging processes, a latent image is formed on a dielectric image receptor or electroreceptor by ion deposition, as described, for example, in U.S. Pat. No. 3,564,556, U.S. Pat. No. 3,611,419, U.S. Pat. No. 4,240,084, U.S. Pat. No. 4,569,584, U.S. Pat. No. 2,919,171, U.S. Pat. No. 4,524,371, U.S. Pat. No. 4,619,515, U.S. Pat. No. 4,463,363, U.S. Pat. No. 4,254,424, U.S. Pat. No. 4,538,163, U.S. Pat. No. 4,409,604, U.S. Pat. No. 4,408,214, U.S. Pat. No. 4,365,549, U.S. Pat. No. 4,267,556, U.S. Pat. No. 4,160,257, and U.S. Pat. No. 4,155,093, the disclosures of each of which are totally incorporated herein by reference. Generally, the process entails application of charge in an image pattern with an ionographic writing head to a dielectric receiver that retains the charged image. The image is subsequently developed with a developer capable of developing charge images.
Many methods are known for applying the electroscopic particles to the electrostatic latent image to be developed. One development method, disclosed in U.S. Pat. No. 2,618,552, the disclosure of which is totally incorporated herein by reference, is known as cascade development. Another technique for developing electrostatic images is the magnetic brush process, disclosed in U.S. Pat. No. 2,874,063. This method entails the carrying of a developer material containing toner and magnetic carrier particles by a magnet. The magnetic field of the magnet causes alignment of the magnetic carriers in a brushlike configuration, and this "magnetic brush" is brought into contact with the electrostatic image bearing surface of the photoreceptor. The toner particles are drawn from the brush to the electrostatic image by electrostatic attraction to the undischarged areas of the photoreceptor, and development of the image results. Other techniques, such as touchdown development, powder cloud development, and jumping development are known to be suitable for developing electrostatic latent images.
Liquid developers and liquid development processes for the development of electrostatic latent images are also known. In electrophoretic developers and processes, the liquid developers generally comprise a liquid vehicle and colored toner particles, and frequently also contain a charge control agent. The colored toner particles become charged, and upon contacting the electrostatic latent image with the liquid developer, the particles migrate through the liquid vehicle toward the charged image, thereby effecting development. Any residual liquid vehicle remaining on the image subsequent to development is evaporated or absorbed into the receiving sheet. Typically, liquid developers employ hydrocarbon liquid vehicles, most commonly high boiling aliphatic hydrocarbons that are relatively high in resistivity and nontoxic. Developers and processes of this type are disclosed in, for example, U.S. Pat. No. 4,476,210, U.S. Pat. No. 2,877,133, U.S. Pat. No. 2,890,174, U.S. Pat. No. 2,899,335, U.S. Pat. No. 2,892,709, U.S. Pat. No. 2,913,353, U.S. Pat. No. 3,729,419, U.S. Pat. No. 3,841,893, U.S. Pat. No. 3,968,044, U.S. Pat. No. 4,794,651, U.S. Pat. No. 4,762,764, U.S. Pat. No. 4,830,945, U.S. Pat. No. 4,686,936, U.S. Pat. No. 4,766,049, U.S. Pat. No. 4,707,429, U.S. Pat. No. 4,780,388, U.S. Pat. No. 3,976,808, U.S. Pat. No. 4,877,698, U.S. Pat. No. 4,880,720, U.S. Pat. No. 4,880,432, and copending application U.S. Ser. No. 07/300,395, the disclosures of each of which are totally incorporated herein by reference.
In polarizable liquid development processes, as disclosed in U.S. Pat. No. 3,084,043 (Gundlach), the disclosure of which is totally incorporated herein by reference, liquid developers having relatively low viscosity and low volatility and relatively high electrical conductivity (relatively low volume resistivity) are deposited on a gravure roller to fill the depressions in the roller surface. Excess developer is removed from the lands between the depressions, and as a receiving surface charged in image configuration passes near the gravure roller, liquid developer is attracted from the depressions onto the receiving surface in image configuration by the charged image. Developers and processes of this type are disclosed in, for example, U.S. Pat. No. 4,047,943, U.S. Pat. No. 4,059,444, U.S. Pat. No. 4,822,710, U.S. Pat. No. 4,804,601, U.S. Pat. No. 4,766,049, Canadian Patent 937,823, Canadian Patent 926,182, Canadian Patent 942,554, British Patent 1,321,286, and British Patent 1,312,844, the disclosures of each of which are totally incorporated herein by reference.
U.S. Pat. No. 4,284,782 (Schmidt), the disclosure of which is totally incorporated herein by reference, discloses a process for the manufacture of 6-hydroxypyrid-2-ones by reacting a cyanoacetamide with an acetoacetic acid ester at temperatures of 50.degree. C. to 200.degree. C. and a pressure of 0.5 to 50 bars in an aqueous solution or suspension in the presence of an amine in a molar amount at least equal to that of the cyanoacetamide reactant. The 6-hydroxypyrid-2-ones are of the general formula ##STR9## wherein R represents hydrogen or an optionally branched alkyl radical having 1 to 4 carbon atoms.
Japanese Patent Publication 04-180968-A discloses a dye represented by the general formula ##STR10## wherein R.sub.1 and R.sub.2 are hydrogen or optionally substituted alkyl and wherein R.sub.1 and R.sub.2 can be formed into a ring of 5 or 6 atoms by bonding with each other, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are halogen, optionally substituted alkyl, optionally substituted alkoxy, optionally substituted amido, or optionally substituted sulphonamide, A, B, and D are either the same or different and are carbon, nitrogen, oxygen, on an organic group or a hydrogen-atom bonding with the pyridone-ring through the sulphur atom. The dye is used for forming color images, such as a cyan colored filter dye used as an image forming medium for a photograph, heat-sensitive transfer printing, ink jet printing, or the like.
While known compositions and processes are useful for their intended purposes, a need remains for improved colorant compositions particularly suitable for use in developer compositions. In addition, a need remains for improved colorant compositions particularly suitable for use in dry toners for developing electrostatic latent images. Further, there is a need for improved colorant compositions particularly suitable for use in liquid developers for developing electrostatic latent images. Additionally, there is a need for toner compositions capable of generating images of high color quality. In addition, there is a need for toner compositions with dye colorants in which lower concentrations of dye are needed to obtain images of the desired color and intensity. Further, there is a need for toner compositions containing colorants which are capable of triboelectrically charging the toner. Additionally, there is a need for toner compositions containing colorants which do not affect the triboelectric charging characteristics of the toner. There is also a need for toner compositions containing dye colorants which do not adversely affect fusing temperatures or characteristics. Further, a need exists for toner compositions containing dye colorants wherein images generated with the toners are of archival quality in that the images are lightfast and permanent. Additionally, there is a need for toner compositions which generate on transparencies images of high projection efficiency and color quality.